U.S. patent number 11,196,145 [Application Number 16/577,365] was granted by the patent office on 2021-12-07 for diversity antenna for bodypack transmitter.
This patent grant is currently assigned to Shure Acquisition Holdings, Inc.. The grantee listed for this patent is Shure Acquisition Holdings, Inc.. Invention is credited to Thomas John Downs, Christopher Richard Knipstein, Christopher Zachara.
United States Patent |
11,196,145 |
Zachara , et al. |
December 7, 2021 |
Diversity antenna for bodypack transmitter
Abstract
Embodiments include an antenna assembly comprising a
non-conductive housing having an open end; an antenna element
positioned inside the non-conductive housing; an electrical cable
having a first end electrically coupled to the antenna element and
a second end extending out from the open end; one or more
dielectric materials positioned inside the non-conductive housing;
and a conductive gasket coupled to a portion of the electrical
cable positioned adjacent to the open end and outside the
non-conductive housing. One embodiment includes a portable wireless
bodypack device comprising a frame having a first external sidewall
opposite a second external sidewall; a first antenna housing
forming a portion of the first sidewall and including a first
diversity antenna; and a second antenna housing forming a portion
of the second sidewall and including a second diversity
antenna.
Inventors: |
Zachara; Christopher (Lake
Bluff, IL), Knipstein; Christopher Richard (Chicago, IL),
Downs; Thomas John (Western Springs, IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
Shure Acquisition Holdings, Inc. |
Niles |
IL |
US |
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Assignee: |
Shure Acquisition Holdings,
Inc. (Niles, IL)
|
Family
ID: |
1000005980179 |
Appl.
No.: |
16/577,365 |
Filed: |
September 20, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200021014 A1 |
Jan 16, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15187514 |
Jun 20, 2016 |
10431873 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01Q
1/50 (20130101); H01Q 9/0421 (20130101); H01Q
1/243 (20130101); H01Q 1/273 (20130101); H01Q
1/42 (20130101); H01Q 1/48 (20130101); H01Q
21/28 (20130101) |
Current International
Class: |
H01Q
1/24 (20060101); H01Q 9/04 (20060101); H01Q
1/50 (20060101); H01Q 21/28 (20060101); H01Q
1/48 (20060101); H01Q 1/42 (20060101); H01Q
1/27 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1292584 |
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Apr 2001 |
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CN |
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102820520 |
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Dec 2012 |
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CN |
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2435549 |
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Aug 2007 |
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GB |
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Other References
International Search Report and Written Opinion for
PCT/US2017/037524 dated Jan. 12, 2017. cited by applicant .
Invitation to Pay Additional Fees for PCT/US2017/037524 dated Sep.
21, 2017. cited by applicant.
|
Primary Examiner: Lopez Cruz; Dimary S
Assistant Examiner: Bouizza; Michael M
Attorney, Agent or Firm: Neal, Gerber & Eisenberg
LLP
Parent Case Text
CROSS-REFERENCE
This application is a continuation of U.S. patent application Ser.
No. 15/187,514, filed on Jun. 20, 2016, the contents of which are
incorporated herein in their entirety.
Claims
The invention claimed is:
1. A portable wireless bodypack device, comprising: a frame having
a first external sidewall opposite a second external sidewall, each
external sidewall including an outer surface and an opening within
the outer surface formed by a recessed portion of the sidewall; a
first antenna housing disposed in the recessed portion of the first
external sidewall and comprising a first antenna element; and a
second antenna housing disposed in the recessed portion of the
second external sidewall and comprising a second antenna element,
wherein each antenna housing includes an enclosed antenna space
defined by a plurality of adjoining sidewalls, the adjoining
sidewalls comprising an external-facing wall configured to
substantially fill the opening in the outer surface of the
corresponding external sidewall.
2. The portable wireless bodypack device of claim 1, wherein a
width of the opening in each external sidewall is substantially
equal to a width of the outer surface of said sidewall.
3. The portable wireless bodypack device of claim 1, wherein each
of the first and second antenna elements is positioned adjacent to
the external-facing wall of the corresponding antenna housing to
maximize a spatial separation between the two antenna elements.
4. The portable wireless bodypack device of claim 1, wherein each
of the first and second external sidewalls includes the recessed
portion in a bottom half of the sidewall.
5. The portable wireless bodypack device of claim 1, wherein the
frame is made of a conductive material, and each of the first and
second antenna housings is made of a non-conductive material.
6. The portable wireless bodypack device of claim 5, further
comprising a conductive front cover coupled to a front surface of
the frame and a conductive back cover coupled to a back surface of
the frame.
7. The portable wireless bodypack device of claim 6, wherein each
antenna housing has a first one of the plurality of adjoining
sidewalls adjacent to the front cover and an opposing one of the
plurality of adjoining sidewalls adjacent to the back cover.
8. The portable wireless bodypack device of claim 6, wherein each
of the first and second antenna elements is centered on the
corresponding external sidewall between the front cover and the
back cover.
9. The portable wireless bodypack device of claim 1, further
comprising: a first electrical cable coupled to the first antenna
element within the first antenna housing and a second electrical
cable coupled to second antenna element within the second antenna
housing, each electrical cable having an outer portion extending
out from the corresponding antenna housing; and a first conductive
gasket coupled to the outer portion of the first electrical cable
and a second conductive gasket coupled to the outer portion of the
second electrical cable.
10. The portable wireless bodypack device of claim 9, wherein each
conductive gasket is configured to contact the frame along at least
two sides of the gasket to provide antenna grounding.
11. The portable wireless bodypack device of claim 1, wherein each
of the first and second antenna housings further comprises a closed
bottom coupled to the sidewalls of the housing and an open top
positioned opposite the closed bottom, the open top being
configured to receive the corresponding antenna element during
assembly.
12. The portable wireless bodypack device of claim 1, wherein each
of the first and second antenna elements is configured for
operation in at least one of the following frequency bands: 1.5
Gigahertz (GHz), 1.8 GHz, 2.4 GHz, 5.7 GHz, 6.9 GHz, and 7.1
GHz.
13. A portable wireless bodypack device, comprising: a frame having
a first external sidewall opposite a second external sidewall and a
top external wall opposite a bottom external wall; a first antenna
housing disposed in the first external sidewall, the first antenna
housing comprising a first antenna element; a second antenna
housing disposed in the second external sidewall, the second
antenna housing comprising a second antenna element; and an
external connector coupled to the top external wall of the frame,
the external connector being configured for electrical connection
to a third antenna disposed outside the frame, wherein the first
and second antenna elements are configured for operation in a
different frequency band than the third antenna connected to the
external connector, and wherein the first and second antenna
elements are positioned closer to the bottom external wall than the
top external wall so as to minimize interactions between the
frequency band of the third antenna and the frequency band of the
first and second antenna elements.
14. The portable wireless bodypack device of claim 13, wherein a
position of each antenna element within the corresponding external
sidewall is selected to minimize cross-band coupling between the
external connector and said antenna element.
15. The portable wireless bodypack device of claim 13, wherein each
of the first and second external sidewalls includes a recess in a
bottom half of said sidewall for receiving the corresponding
antenna housing.
16. The portable wireless bodypack device of claim 13, wherein the
first and second antenna elements are configured for diversity
operation in one or more high frequency bands, and the third
antenna is configured for operation in a low frequency band.
17. The portable wireless bodypack device of claim 13, wherein each
of the first and second antenna elements is configured for
operation in at least one of the following frequency bands: 1.5
Gigahertz (GHz), 1.8 GHz, 2.4 GHz, 5.7 GHz, 6.9 GHz, and 7.1
GHz.
18. The portable wireless bodypack device of claim 13, wherein each
of the first and second antenna housings comprises an
external-facing wall configured to form part of the corresponding
external sidewall.
19. The portable wireless bodypack device of claim 13, wherein each
of the first and second antenna elements is positioned adjacent to
the external-facing wall of the corresponding antenna housing to
maximize a spatial separation between the two antenna elements.
20. The portable wireless bodypack device of claim 13, wherein the
frame is made of a conductive material, and each of the first and
second antenna housings is made of a non-conductive material.
21. The portable wireless bodypack device of claim 13, wherein the
frame has a generally rectangular shape formed by the top and
bottom external walls being shorter in length than the first and
second external sidewalls.
Description
TECHNICAL FIELD
This application generally relates to portable wireless
communication devices, and more specifically, to antennas included
in wireless bodypack devices, such as wireless bodypack
transmitters and/or receivers.
BACKGROUND
Portable wireless communication devices, such as wireless
microphones, wireless audio transmitters, wireless audio receivers,
and wireless earphones, include antennas for communicating radio
frequency (RF) signals without the need for a physical cable. The
RF signals can include digital or analog signals, such as modulated
audio signals, data signals, and/or control signals. Portable
wireless communication devices are used for many functions,
including, for example, enabling broadcasters and other video
programming networks to perform electronic news gathering (ENG)
activities at locations in the field and the broadcasting of live
sports events. Portable wireless communication devices are also
used by, for example, stage performers, singers, and/or actors in
theaters, music venues, and film studios, and public speakers at
conventions, corporate events, houses of worship, schools, and
sporting events.
One common type of portable wireless communication device is a
wireless bodypack microphone transmitter, which is typically
secured on the body of a user (e.g., with belt clips, straps, tape,
etc.) and is in communication with a wireless microphone (such as,
e.g., a handheld unit, a body-worn device, or an in-ear monitor)
and a remote receiver (e.g., an audio amplifier or recording
device). Another common type of portable wireless communication
device is a wireless bodypack personal monitor receiver, which is
also typically secured on the body of the user (e.g., with belt
clips, straps, tape, etc.) and is in communication with wireless
earphones or other personal monitor (e.g., in-ear monitor,
headphones or other headset) and a remote transmitter (e.g., an
audio source).
The antennas included in the portable wireless communication
devices can be designed to operate in certain spectrum band(s), and
may be designed to cover either a discrete set of frequencies
within the spectrum band or an entire range of frequencies in the
band. The spectrum band in which a portable wireless communication
device operates can determine which technical rules and/or
government regulations apply to that device.
For example, the Federal Communications Commission (FCC) allows the
use of wireless microphones on a licensed and unlicensed basis,
depending on the spectrum band. Most wireless microphone systems
that operate today use spectrum within the "Ultra High Frequency"
(UHF) bands that are currently designated for television (TV)
(e.g., TV channels 2 to 51, except channel 37). Currently, wireless
microphone users need a license from the FCC in order to operate in
the UHF/TV bands (e.g., 470-698 MHz). However, the amount of
spectrum in the TV bands available for wireless microphones is set
to decrease once the FCC conducts the Broadcast Television
Incentive Auction. This Auction will repurpose a portion of the TV
band spectrum--the 600 MHz--for new wireless services, making this
band no longer available for wireless microphone use. Wireless
microphone systems can also be designed for operation in the
currently licensed "Very High Frequency" (VHF) bands, which cover
the 30-300 MHz range.
An increasing number of wireless microphone systems are being
developed for operation in other spectrum bands on an unlicensed
basis, including, for example, the 902-928 MHz band, the 1920-1930
MHz band (i.e. the 1.9 GHz or "DECT" band; also included within the
1.8 GHz band), and the 2.4-2.483 GHz band (i.e. "ZigBee" or IEEE
802.15.4; referred to herein as the "2.4 GHz band"). However, given
the vast difference in frequency between, for example, the UHF/TV
bands and the ZigBee band, wireless microphone systems that are
specifically designed for one of these two spectrums typically
cannot be repurposed for the other spectrum without replacing the
existing antenna(s).
Moreover, antenna design considerations can limit the number of
antennas that are included within a single device (e.g., due to a
lack of available space), while aesthetic design considerations can
restrict the type of antennas that can be used. For example,
wireless bodypack transmitters and/or receivers typically include a
reduced-size antenna that is at least partially integrated into the
bodypack housing to keep the overall package size small and
comfortable to use or wear. However, this limitation in antenna
size/space makes it difficult for the wireless bodypack device to
provide sufficient radiated efficiency and broadband antenna
coverage.
Accordingly, there is a need for a wireless bodypack device that
can adapt to changes in spectrum availability, but still provide
consistent, high quality, broadband performance with a low-cost,
aesthetically-pleasing design.
SUMMARY
The invention is intended to solve the above-noted problems by
providing systems and methods that are designed to provide, among
other things, (1) an antenna assembly configured to fully encase an
antenna element within a dielectrically-loaded antenna housing, (2)
a portable wireless bodypack device configured to support two
separate antenna housings with maximum spatial diversity
therebetween, and (3) a process for manufacturing the antenna
assembly.
Example embodiments include an antenna assembly comprising a
non-conductive housing having an open end; an antenna element
positioned inside the non-conductive housing; an electrical cable
having a first end electrically coupled to the antenna element and
a second end extending out from the open end of the non-conductive
housing; one or more dielectric materials positioned inside the
non-conductive housing; and a conductive gasket coupled to a
portion of the electrical cable positioned adjacent to the open end
and outside the non-conductive housing.
Another example embodiment includes a portable wireless bodypack
device comprising a frame having a first external sidewall opposite
a second external sidewall; a first antenna housing forming a
portion of the first external sidewall, the first antenna housing
including a first diversity antenna; and a second antenna housing
forming a portion of the second external sidewall, the second
antenna housing including a second diversity antenna.
Another example embodiment includes a method of manufacturing an
antenna assembly for a portable wireless bodypack device. The
method includes forming the antenna assembly by depositing a first
dielectric material into an open end of an antenna housing
comprising an antenna element and at least one additional
dielectric material, and coupling a conductive gasket to an
electrical cable coupled to the antenna housing, the conductive
gasket being coupled adjacent to the open end and outside the
antenna housing.
These and other embodiments, and various permutations and aspects,
will become apparent and be more fully understood from the
following detailed description and accompanying drawings, which set
forth illustrative embodiments that are indicative of the various
ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a front perspective view of an example portable wireless
bodypack device, in accordance with certain embodiments.
FIG. 1B is a rear perspective view of the portable wireless
bodypack device of FIG. 1, in accordance with certain
embodiments.
FIG. 2 is a partially exploded rear perspective view of an example
frame and an example back cover of the portable wireless bodypack
device of FIG. 1, in accordance with certain embodiments.
FIG. 3 is a partially exploded rear perspective view of the frame
shown in FIG. 2 and two example antenna assemblies coupled to the
frame, in accordance with certain embodiments.
FIG. 4 is a partial front view of example internal circuitry
components coupled to the frame shown in FIG. 2, in accordance with
certain embodiments.
FIG. 5 is a top perspective view of an example antenna assembly, in
accordance with certain embodiments.
FIG. 6 is a partially transparent top perspective view of the
antenna assembly shown in FIG. 5, in accordance with certain
embodiments.
FIG. 7 is a close-up view of a first subassembly included in the
antenna assembly shown in FIG. 5, in accordance with certain
embodiments.
FIG. 8 is a perspective view of the first subassembly of FIG. 7 and
an antenna housing of the antenna assembly of FIG. 5 during a first
stage of fabrication, in accordance with certain embodiments.
FIG. 9 is a partially transparent view of a second subassembly of
the antenna assembly of FIG. 5 during a second stage of
fabrication, in accordance with certain embodiments.
FIG. 10 is a partially transparent view of a third subassembly and
a conductive gasket of the antenna assembly shown in FIG. 5 during
a third stage of fabrication, in accordance with certain
embodiments.
FIG. 11 is a close-up view of a portion of the antenna assembly
installed in the frame of FIG. 2, in accordance with certain
embodiments.
FIG. 12 is a top perspective view of the portable wireless bodypack
device shown in FIG. 1, in accordance with certain embodiments.
FIG. 13 is a cross-sectional view of the portable wireless bodypack
device shown in FIG. 12, in accordance with certain
embodiments.
FIG. 14 is a perspective view of a portion of the frame shown in
FIG. 3 and an example front cover coupled thereto, in accordance
with certain embodiments.
FIG. 15 is a cross-sectional view of another example portable
wireless bodypack device with alternative antenna placement, in
accordance with certain embodiments.
DETAILED DESCRIPTION
The description that follows describes, illustrates and exemplifies
one or more particular embodiments of the invention in accordance
with its principles. This description is not provided to limit the
invention to the embodiments described herein, but rather to
explain and teach the principles of the invention in such a way as
to enable one of ordinary skill in the art to understand these
principles and, with that understanding, be able to apply them to
practice not only the embodiments described herein, but also other
embodiments that may come to mind in accordance with these
principles. The scope of the invention is intended to cover all
such embodiments that may fall within the scope of the appended
claims, either literally or under the doctrine of equivalents.
It should be noted that in the description and drawings, like or
substantially similar elements may be labeled with the same
reference numerals. However, sometimes these elements may be
labeled with differing numbers, such as, for example, in cases
where such labeling facilitates a more clear description.
Additionally, the drawings set forth herein are not necessarily
drawn to scale, and in some instances proportions may have been
exaggerated to more clearly depict certain features. Such labeling
and drawing practices do not necessarily implicate an underlying
substantive purpose. As stated above, the specification is intended
to be taken as a whole and interpreted in accordance with the
principles of the invention as taught herein and understood to one
of ordinary skill in the art.
With respect to the exemplary systems, components and architecture
described and illustrated herein, it should also be understood that
the embodiments may be embodied by, or employed in, numerous
configurations and components, including one or more systems,
hardware, software, or firmware configurations or components, or
any combination thereof, as understood by one of ordinary skill in
the art. Accordingly, while the drawings illustrate exemplary
systems including components for one or more of the embodiments
contemplated herein, it should be understood that with respect to
each embodiment, one or more components may not be present or
necessary in the system.
FIGS. 1A and 1B depict front and rear perspective views of an
example portable wireless bodypack device 100 (also referred to
herein as a "bodypack device"), such as, for example, a portable
wireless bodypack transmitter for use with a wireless microphone
(not shown), in accordance with embodiments. Although the
embodiments described herein are explained in the context of a
bodypack transmitter, the term "bodypack device" is used herein to
include both transmitters and receivers, such as, for example, a
portable wireless bodypack receiver for use with a wireless
personal monitor.
As illustrated, the bodypack device 100 includes a front cover 102
and a back cover 104 positioned on opposite sides of the device 100
and a frame 106 coupled therebetween. The frame 106 can form left
and right external sidewalls 108a and 108b of the bodypack device
100, as well as top and bottom external sides 108c and 108d of the
device 100. In embodiments, the frame 106 can also extend around a
top, front section of the bodypack device 100 to form an upper
front surface portion 108e of the bodypack device 100. As shown,
the upper front surface portion 108e can be configured to carry
and/or support a display screen and to receive the front cover 102.
In such cases, the front cover 102 may form only a lower portion of
the front surface of the bodypack device 100.
Referring additionally to FIGS. 2 and 3, shown are rear perspective
views of the frame 106 of the bodypack device 100, in accordance
with embodiments. The front cover 102 can be coupled to a front
surface 106a of the frame 106, below the upper front surface
portion 108e, and the back cover 104 can be coupled to a back
surface 106b of the frame 106, as shown in FIG. 2. Accordingly, the
front cover 102 and the back cover 104 can be separated from each
other by a width of the frame 106, as shown in FIG. 1.
In embodiments, the front cover 102, the back cover 104, and the
frame 106 join together to form an enclosure for housing various
electrical components of the bodypack device 100. For example,
referring additionally to FIG. 4, shown is an example circuit board
111 comprising the various electrical components of the bodypack
device 100, including circuitry for the display screen, a power
source, a wireless communication unit, and one or more audio
components. As illustrated, the circuit board 111 can be positioned
in the frame 106 between upper front surface portion 108e and the
back cover 104. According to embodiments, the circuit board 111 can
be any type of circuit board, including, for example, a printed
circuit board, as shown in FIG. 4.
As shown in FIGS. 1-4, the bodypack device 100 further includes a
set of antenna assemblies 112a and 112b that are arranged on
opposite sidewalls 108a and 108b of the device 100. In embodiments,
the antenna assemblies 112a and 112b are configured to be fully
integrated or embedded into the enclosure of the bodypack device
100, so as to maintain an existing form factor of the bodypack
device 100. For example, as shown in FIGS. 1A and 1B, each antenna
assembly 112a, 112b forms a portion of, and/or is flush with, the
corresponding sidewall 108a, 108b. In addition, as shown in FIGS. 2
and 3, the antenna assemblies 112a and 112b are configured to fit
completely within corresponding slots 114 included in the
respective sidewalls 108a and 108b, so as to not occupy any space
on an exterior of the bodypack device 100. In embodiments, due at
least to the conformal structure and symmetrical placement of the
antenna assemblies 112a and 112b in opposing sidewalls 108a and
108b, the antenna assemblies 112a and 112b can be configured to be
mirror images of each other, as shown in FIGS. 2 and 3.
More specifically, each antenna assembly 112a, 112b includes an
antenna housing 116 configured to enclose an antenna element (such
as, e.g., antenna element 202 in FIG. 7), an electrical cable 118
having a first end coupled to the antenna element inside the
antenna housing 116 and a second end extending out from the antenna
housing 116, and a conductive gasket 120 coupled to the electrical
cable 118 adjacent to and outside the antenna housing 116. As shown
in FIG. 3, the slot 114 for receiving a corresponding antenna
assembly 112a, 112b in the respective sidewall 108a, 108b includes
an external opening 122 for receiving the antenna housing 116 and
an internal channel 124 for receiving the electrical cable 118 and
the conductive gasket 120. The internal channel 124 extends from a
top end of the external opening 122 and runs along an interior of
the corresponding sidewall 108a, 108b towards the top side 108c of
the bodypack device 100. The external opening 122 forms a break in
the corresponding sidewall 108a, 108b and has a width substantially
equal to a width of the corresponding sidewall 108a, 108b.
In embodiments, a width, depth, and overall shape of the antenna
housing 116 can be configured according to a width, depth, and
shape of the external opening 122, so that the antenna housing 116
conforms to or fills the entire opening 122. For example, as shown
in FIGS. 1-3, an outer wall of the antenna housing 116 can mesh
with an exterior wall of the bodypack device 100, or more
specifically, form a portion of the respective external sidewall
108a, 108b, and the front and back sides of the antenna housing 116
can be substantially flush with the front surface 106a and back
surface 106b, respectively, of the frame 106.
Also in embodiments, a width, depth, and overall shape of the
conductive gasket 120 can be configured according to a width,
depth, and shape of the internal channel 124, respectively, so that
the conductive gasket 120 fits snugly into the internal channel 124
and around the cable 118. In some embodiments, the conductive
gasket 120 is made from a compressible material, such as rubber,
that enables the sides of the conductive gasket 120 to be
compressed as the gasket 120 is pressed into the internal channel
124, so as to create a hermetic seal between the conductive gasket
120 and the internal channel 124. In some embodiments, the
conductive gasket 120 is further compressed into the internal
channel 124 upon placement of the back cover 104 over the frame
106, for example, due to pressure applied by one or more ribs 125
along the interior edges of the back cover 104, as shown in FIG.
2.
As shown in FIG. 4, the electrical cables 118 can be configured to
electrically connect the antenna assemblies 112a and 112b to the
circuit board 111. For example, each electrical cable 118 can
include a plug 126 (e.g., an MHF plug) coupled to the cable 118
opposite the antenna housing 116, and the circuit board 111 can
include corresponding connectors 128 (e.g., MHF receptacles) for
receiving the plugs 126. In embodiments, the electrical cable 118
can be a coaxial cable or other type of communication cable
appropriate for carrying wireless signals between the antenna
element of the antenna assembly 112 and the circuit board 111.
In embodiments, the bodypack device 100 can include an additional,
external or whip antenna (e.g., a WIP antenna) coupled to a
connector 130 (e.g., SMA connector) included on the top side 108c
of the device 100 and electrically coupled to the circuit board
111. In one example embodiment, the external antenna can be
configured for operation in a licensed UHF band, and the antenna
assemblies 112a and 112b can be configured for diversity operation
in the 2.4 Gigahertz (GHz) band (e.g., for control link signals).
In other embodiments, the antenna assemblies 112a and 112b and/or
the external antenna can be configured for operation in any of the
following frequency bands: 1.5 GHz, 1.8 GHz (which includes the 1.9
GHz or "DECT" band), 2.4 GHz (such as, e.g., the Zigbee band), 5.7
GHz, 6.9 GHz, and 7.1 GHz. As will be understood by one of ordinary
skill in the art, each of these frequency bands covers or includes
a range of frequencies surrounding the named frequency.
The function of the external antenna can vary depending on the type
of bodypack device 100. For example, in the case of a wireless
bodypack microphone transmitter, the external antenna can be
configured to receive wireless signals from a wireless microphone,
while the antenna assemblies 112a and 112b can be configured to
transmit the received wireless signals to a remote receiver. As
another example, in the case of a wireless bodypack personal
monitor receiver, the antenna assemblies 112a and 112b can be
configured to receive wireless signals from a remote transmitter,
while the external antenna can be configured to transmit the
received wireless signals to a wireless personal monitor.
In embodiments, the placement of the antenna assemblies 112a, 112b
on respective sidewalls 108a, 108b can be configured to maximize a
distance between the antenna elements included in each assembly 112
and the external antenna, and/or the connector 130 coupled thereto.
For example, as shown in FIG. 1A, a bottom end of each antenna
assembly 112a, 112b (and therefore, a bottom end of the antenna
element included therein) can be positioned closer to the bottom
side 108d of the frame 106 than to the top side 108c, which
includes the external antenna connector 130. In embodiments, the
distance between the external antenna and each antenna assembly
112a, 112b can be selected to help minimize undesirable
interactions between the operational frequency bands of each
antenna, such as, for example, generation of intermodulation
products, receiver overloading effects, etc.
According to embodiments, each of the front cover 102, the back
cover 104, and the frame 106 can be made from a sturdy, conductive
material, such as metal, to provide radio frequency (RF) shielding
for the internal components of the device 100. The antenna housing
116, on the other hand, can be made of a non-conductive material,
such as plastic, to facilitate wireless communication via the
antenna element included in the antenna housing 116. As will be
appreciated, antenna detuning can occur when an antenna element is
placed in close proximity to conductive or metal parts and/or
placed on or near a human body. In embodiments, the non-conductive
antenna housing 116 can be arranged within the conductive enclosure
of the bodypack device 100 so as to minimize this antenna detuning
and achieve high antenna efficiency, as well as, for example,
minimize RF interference between the antenna within the antenna
housing 116 and the internal circuitry included on the circuit
board 111 and/or mitigate RF link failure caused by interference
between the antennas of the bodypack device 100.
For example, as shown in FIGS. 1A and 1B, each antenna assembly
112a, 112b can be centered on the corresponding sidewall 108a, 108b
between the front cover 102 and the back cover 104 of the device
100. This arrangement of the antenna assemblies 112a and 112b
utilizes the conductive covers 102 and 104 to, for example,
maximize a spatial isolation of the antenna elements from human
body interference, which can mitigate the effects of human body
detuning and improve antenna efficiency.
In addition, as shown in FIGS. 2 and 3, each non-conductive antenna
housing 116 can be encased within the respective sidewall 108a,
108b of the conductive frame 106 on the top, bottom, and inner
sides, and between the conductive front and back covers 102 and 104
on the front and back sides, with the remaining side of the housing
116 facing an exterior of the bodypack housing 100. This
arrangement of the antenna housings 116 within the conductive
enclosure of the bodypack device 100 shields the internal circuitry
of the bodypack device 100 from any RF interference conducted
and/or radiated by the antenna elements of the antenna housings
116.
As also shown in FIGS. 2 and 3, the antenna assemblies 112a and
112b can be arranged within opposite sidewalls 108a and 108b,
respectively, so that the antenna elements therein are separated by
the entire width of the bodypack device 100. This arrangement
provides, for example, maximum spatial separation of the antenna
elements, while still keeping the antenna assemblies 112a and 112b
completely integrated into the bodypack device 100. Due to this
physical separation, the antenna elements can operate as diversity
antennas that cover the same or similar RF bands (e.g., 1.5 GHz,
1.8 GHz, 2.4 GHz (e.g., the Zigbee band), 5.7 GHz, 6.9 GHz, 7.1
GHz, etc.) with maximum diversity gain and without generating
undesirable effects, such as, for example, intermodulation
products. Such spatial diversity can also help prevent, or reduce
the probability of, RF link failure, at least because the antennas
can serve as back-ups for each other in the event of failure by one
of the antennas due to, for example, human body detuning.
FIGS. 5 and 6 illustrate an example antenna assembly 200 configured
for insertion into the frame 106 shown in FIGS. 2 and 3, in
accordance with embodiments. In the illustrated embodiments, the
antenna assembly 200 is similar to the antenna assembly 112b shown
in FIG. 3 and includes the antenna housing 116, the electrical
cable 118, the conductive gasket 120, and the electrical plug 126
described herein with respect to the antenna assemblies 112a and
112b. FIG. 5 depicts the antenna assembly 200 as fully assembled
and ready for insertion into the frame 106. FIG. 6 depicts the
antenna assembly 200 with a partially transparent antenna housing
116 for ease of illustration and to facilitate description of the
components inside the antenna housing 116. It should be appreciated
that, although the embodiments of the antenna assembly 200
described herein are explained in the context of the antenna
assembly 112b, the same techniques can be used to implement the
antenna assembly 112a by producing a mirror image of the antenna
assembly 200.
As shown in FIG. 6, the antenna housing 116 fully encases an
antenna element 202 and one or more dielectric materials, such as,
for example, a first dielectric portion 204, a second dielectric
portion 206, and/or a third dielectric portion 208, in accordance
with embodiments. The one or more dielectric materials are
preferably low loss, dielectrically-loaded materials selected to
achieve high antenna efficiency for the antenna element 202. For
example, the one or more dielectric materials may provide a higher
dielectric constant, alone or in combination with each other, that
can compensate for an electrically short antenna element 202, or
otherwise increase the electrical length of the antenna element
202.
In embodiments, the first dielectric portion 204 is a foam pad made
of, for example, PORON.RTM. or other suitable electrically
conductive foam. The second dielectric portion 206 is made from an
epoxy or epoxy resin, such as, for example, a Flex Epoxy
manufactured by Sigma Plastronics, or any other suitable epoxy
material. And the third dielectric portion 208 comprises air or
other suitable dielectric material. As shown in FIG. 6, the first
dielectric portion 204 (also referred to herein as the "foam
portion") can be positioned adjacent to the antenna element 202 and
between the second dielectric portion 206 (also referred to herein
as the "epoxy portion") and the third dielectric portion 208 (also
referred to herein as the "air portion"). As also shown, the third
dielectric portion 208 can be positioned between the foam portion
204 and an inner end 210 of the antenna element 202, and the epoxy
portion 206 can be positioned between the foam portion 204 and an
open end 212 of the antenna housing 116. In embodiments, the epoxy
portion 206 can be configured to environmentally seal the open end
212 of the antenna housing 116, while an opposite end 214 of the
antenna housing 116 can be fully closed, thereby providing the
antenna element 202 with protection from moisture, debris, and
other external factors on both ends.
In embodiments, the antenna assembly 200 can be assembled in
multiple stages that are designed to preserve the structural
integrity and electrical properties of the antenna element 202. For
example, FIGS. 7-10 illustrate various stages of fabrication during
an example process for manufacturing the antenna assembly 200, in
accordance with embodiments. The manufacturing process may be
performed at one facility or at multiple facilities. For example,
in some cases, one or more steps may be performed at a
pre-fabrication facility, and the remaining steps may be performed
at a finishing facility.
Referring initially to FIG. 7, shown is an example first
subassembly 216 of the antenna assembly 200, in accordance with
embodiments. As shown, the first subassembly 216 includes the
antenna element 202, the foam portion 204, and the electrical cable
118. In embodiments, the first end of the electrical cable 118 may
be coupled to the antenna element 202 at a connection point 217
that also serves as a feed point of the antenna 202, and the foam
portion 204 may be adhered to the antenna element 202 adjacent to
the feed point 217. The antenna element 202 can be formed from one
or more sheets of metal, or other suitable conductive material,
using known metal forming techniques. According to embodiments, the
antenna element 202 can be configured to be any suitable type of
antenna, such as, e.g., an inverted-F antenna, planar inverted-F
antenna (PIFA), modified inverted-F antenna, inverted-L antenna,
dual inverted-L antenna, or hybrids of these antenna structures. In
addition, the antenna 202 can be configured to cover any desired
operating band, including, for example, the 1.5 GHz, the 1.8 GHz
band, the 2.4 GHz band, the 5.7 GHz band, the 6.9 GHz band, and/or
the 7.1 GHz band, for transmission and/or reception of audio
signals, data signals, and/or control link signals.
As shown in FIG. 7, the antenna element 202 (also referred to
herein as an "antenna") includes an elongated main body 218 that
extends between the inner end 210 and an opposing outer end 220,
and one or more structures that are formed from or extend off of
the main body 218. For example, in the illustrated embodiment, the
inner end 210 of the antenna 202 extends perpendicularly from the
main body 218 of the antenna 202 to form an "L-shaped" structure or
leg that substantially spans the width of the antenna housing 116.
The outer end 220 of the antenna 202 extends perpendicularly from
the main body 218 as well, but also curves back around to form a
spiral-like structure, as shown in FIG. 7. In addition, the antenna
element 202 includes a feed structure 222 and a base structure 224,
both extending perpendicularly from the main body 218 of the
antenna 202 and being configured for attachment to the electrical
cable 118.
As shown, the electrical cable 118 extends through the base
structure 224 and ends upon connection to the feed structure 222 at
the feed point 217. In embodiments, the electrical cable 118 can be
a micro-coaxial cable or other communication cable having a
non-conductive outer sleeve 118a (also referred to as a "plastic
jacket") covering an inner shield 118b (also referred to as a
"metallic braid") which, in turn, covers a conductive core 118c
(also referred to as a "center conductor"). As depicted in FIG. 7,
certain portions of the electrical cable 118 may be trimmed to
expose the inner shield 118b and/or the conductive core 118c of the
cable 118 to provide an electrical connection between the cable 118
and the antenna element 202. For example, the inner shield 118b may
be exposed in the portion of the cable 118 that is coupled to an
exterior of the base structure 224 and extends towards the plug
126, and is substantially covered by the conductive gasket 120, as
shown in FIG. 6. In such cases, the inner shield 118b may be
soldered to the exterior of the base structure 224. The conductive
core 118c may be exposed in the portion of the cable 118 that
extends between the structures 222 and 224. In such cases, the
conductive core 118c may be soldered to the feed structure 222 at
the connection point 217, thus providing the antenna feed
point.
In embodiments, the size, shape, and configuration of the main body
218, as well as the one or more structures 210, 220, 222, and 224,
can be configured to implement the desired type of antenna, achieve
a desired antenna length, provide appropriate impedance matching,
or otherwise optimize antenna performance in the desired frequency
band(s), and/or conform the antenna element 202 to the geometry of
the slot 114 within the respective sidewall 108a, 108b (or other
space available for the antenna assembly 200 inside the frame 106).
For example, a width and length of the main body 218 can be
selected based on a depth and length of the slot 114 shown in FIG.
3, while the overall shape of the antenna element 202 can be
selected to achieve a desired antenna length and type. As another
example, a distance between the base structure 224 and the feed
structure 222 can be selected to optimize the impedance matching
for the antenna 202.
As yet another example, in embodiments, the spiral structure of the
outer end 220 can be configured according to a shape or
configuration of the internal channel 124 that receives the outer
end 220 of the antenna 202 when the antenna assembly 200 is placed
into the frame 106. In embodiments, the shape and placement of the
outer end 220 can also be configured to create a grounding element
for the antenna 202. In such cases, the outer end 220 may operate
as a spring finger or metal clip designed to provide antenna
grounding. To illustrate, FIG. 11 depicts the antenna assembly 200
coupled to the sidewall 108b of the frame 106, but with the
conductive gasket 120 and the electrical cable 118 removed in order
to reveal the outer end 220 of the antenna 202. As shown, the outer
end 220 fits into a recess of the internal channel 124 and curves
around so as to fill the recess but avoid contact with the walls of
the recess, except for a contact wall 226. As also shown, a planar
portion of the outer end 220 also touches an opposite side of the
contact wall 226. According to embodiments, these two contacts
between the outer end 220 and the contact wall 226 of the
conductive frame 106 can create a grounding post during operation
of the antenna element 202. Placement of the outer end 220 into the
recess of the internal channel 124 can also help hold the antenna
assembly 200 in place and/or prevent the antenna assembly 200 from
moving within the slot 114.
Referring now to FIG. 8, shown is the first subassembly 216 and the
antenna housing 116 during a first stage in the process for
manufacturing the antenna assembly 200, in accordance with
embodiments. During the first stage, the first subassembly 216 is
inserted into the antenna housing 116 to form a second subassembly
228 (shown in FIG. 9). As shown in FIG. 6, the first subassembly
216 is not fully inserted into the antenna housing 116. Rather, at
least the outer end 220 remains outside of the antenna housing 116,
as shown in FIG. 9. In embodiments, the foam pad 204 can be
configured to align the antenna element 202 within the antenna
housing 116 and/or against the inside of the housing 116. For
example, the foam pad 204 can have a size and shape that is
configured to fit snugly against the inside of the antenna housing
116 and therefore, can prevent the antenna element 202 from moving
around or being jostled while inside the housing 116. In some
cases, the foam pad 204 may be at least slightly compressed as the
subassembly 216 is slid into the housing 116 in order to form a
tight seal between the foam pad 204 and the inside of the housing
116.
FIG. 9 illustrates the second subassembly 228 during a second stage
in the process for manufacturing the antenna assembly 200, in
accordance with embodiments. During the second stage, the epoxy
material (not shown) is dispensed into the open end 212 of the
antenna housing 116 to form the epoxy portion 206 of the antenna
assembly 200. For example, the epoxy material may be deposited into
the housing 116 in a liquid or spreadable form and then hardened or
set into place, for example, using a curing process. In
embodiments, the foam pad 204 can be configured to serve as a base
for limiting a downward flow of the epoxy material, for example, by
forming a liquid-proof seal with the side walls of the antenna
housing 116. In such cases, the epoxy portion 206 may be formed by
completely filling the space between the foam pad 204 and the open
end 212 of the antenna housing 116 with the epoxy material, for
example, as shown in FIG. 10. Once the epoxy portion 206 is formed,
the structures 222 and 224, or more specifically, the two points of
connection between the cable 118 and the antenna element 202, may
be potted within the epoxy material, and the open end 212 of the
antenna housing 116 may be environmentally sealed by the epoxy
material.
FIG. 10 illustrates a third subassembly 230 during a third stage in
the process for manufacturing the antenna assembly 200, in
accordance with embodiments. As shown, the third subassembly 230
includes the second subassembly 228 with the epoxy portion 206 in
place. During the third stage, the conductive gasket 120 is coupled
to the third subassembly 230 by inserting the inner shield 118b of
the electrical cable 118 into a central slot 232 of the conductive
gasket 120. In embodiments, the conductive gasket 120 can be made
of conductive rubber (such as, e.g., a conductive elastomer
manufactured by Chomerics.RTM.) or other suitable compressible
material that includes metal or other conductive pieces therein.
The size and shape of the conductive gasket 120 may be configured
to fit around or onto the third subassembly 230 and/or into the
internal channel 124 of the frame 106. For example, as shown in
FIG. 6, a first portion 120a of the conductive gasket 120 may be
configured to rest above, or be supported by, the metal clip formed
at the outer end 220. And a second portion 120b of the conductive
gasket 120 may be configured to extend down past the first portion
120a, so that a bottom side of the second portion 120b contacts the
frame 106 when the antenna assembly 200 is inserted into the
internal channel 124. Once the third stage is completed, the
antenna assembly 200 is fully assembled, for example, as shown in
FIG. 5, and ready for insertion into the frame 106.
In embodiments, the conductive gasket 120 can be configured to
serve as a secondary grounding element for the antenna 202, in
addition to the metal clip formed by the outer end 220 of the
antenna 202. In particular, the central slot 232 of the gasket 120
may be sized and shaped to securely fit around and/or contact the
inner shield 118b on at least three sides. In addition, the sides
of the central slot 232 may become further compressed around the
inner shield 118b as the gasket 120 is pressed into the internal
channel 124 of the frame 106. Due to the electrical properties of
both the conductive gasket 120 and the inner shield 118b, this
compressed contact between the metal braid of the shield 118b and
the conductive rubber of the gasket 120, and the surrounding
contact between the conductive gasket 120 and the internal channel
124, can provide an electrical ground path between the frame 106
and the inner shield 118b, thus forming the secondary antenna
ground. In embodiments, the compressed contact between the
conductive gasket 120 and the inner shield 118b also protects the
inner shield 118b from RF interference and reduces noise.
In some embodiments, other components of the portable wireless
bodypack device 100 can help further improve performance of the
antenna assembly 200, for example, by ensuring a mechanical
accuracy of the antenna assembly 200 and/or providing additional
grounding points for the antenna 202 to help suppress or minimize
any parasitic resonances (e.g., capacitance and/or inductance)
resulting from the bodypack device 100. For example, when the back
cover 104 is secured to the frame 106, the one or more ribs 125 on
the inside edges of the back cover 104 may press the antenna
assembly 200 into place and help keep the antenna assembly 200
secure during jerking or other movement of the device 100. As
another example, FIGS. 12-14 show additional ground locations that
are formed by the front cover or door 102 and certain points of
connection with the conductive frame 106 and are configured to help
avoid parasitic resonances from the device 100, in accordance with
embodiments.
In particular, FIG. 12 shows that the front door 102 can be secured
to the frame 106 using a pair of latches 234 positioned on opposite
sides of the door 102. In embodiments, the latches 234 are made of
metal or other conductive material. FIG. 13 provides a partial
cross-sectional view of one side of the bodypack device 100, and
shows that each latch 234 makes contact with, or latches onto, the
conductive frame 106 at a point 236. In embodiments, these points
of contact 236 between the conductive latches 234 of the door 102
and the conductive frame 106 on each side of the device 100 can
form solid electrical contacts that provide additional ground
locations for the antenna 202, and thereby help suppress parasitic
resonances from the bodypack device 100. Similarly, FIG. 14 shows
that the front door 102 is coupled to the frame 106 by a pair of
hinges 238. In embodiments, the hinges 238 are made of metal or
other conductive material and include spring pins that secure the
front door 102 to the bottom of the conductive frame 106 or the
back surface 106b. The solid electrical contact between the hinges
238 and the frame 106 can form additional ground locations for the
antenna 202 that also help avoid parasitic resonances of the
bodypack device 100.
FIG. 15 illustrates a cross-sectional view of another example
portable wireless bodypack device 300, in accordance with
embodiments. The bodypack device 300 may be substantially similar
to the bodypack device 100 shown in FIGS. 1A and 1B, except for the
design and placement of diversity antennas 302. For example, the
bodypack device 300 includes a front cover (not shown) and a back
cover 304 coupled to a conductive frame 306 to form an enclosure
for housing various electronic components, including a printed
circuit board 311 and antennas 302. However, as shown in FIG. 12,
the antennas 302 are positioned along a top portion of respective
sidewalls 308 of the frame 306 and/or adjacent to opposing top
corners of the device 300. In addition, as shown in FIG. 15, a
shape of the antennas 302 is configured to conform to the
three-panel shape of the sidewalls 308 and/or the frame 306. For
example, the antenna 302 may be formed by bending or folding a
sheet of metal into three panels, the center panel coinciding with
the width of the sidewall 308a, 308b and the two side panels
wrapping around the frame 306 on either side of the respective
sidewall 308a, 308b. Moreover, instead of using electrical cables
to connect the antennas to the circuit board, the antennas 302 may
be electrically connected to the circuit board 311 using pogo pins
or metal spring fingers 310 that are connected directly to the
circuit board 311 (e.g., via soldering). In some cases, an
electrical cable 318 may be used to connect an input point 319 of
the antennas 302 to appropriate circuitry 320 on the board 311. In
other cases, the circuitry 320 may be positioned on the circuit
board 311 so that the cable 318 is not required. Accordingly, the
antenna arrangement of the body pack device 300 may provide a
mechanical structure that is simpler and easier to implement.
Thus, the embodiments described herein provide an enhanced portable
wireless bodypack transmitter or receiver with diversity antennas
strategically positioned on opposing sides of the bodypack housing
to help minimize radio frequency (RF) link loss due to human body
detuning. The diversity antennas can be configured for
implementation in the 2.4 GHz band or other high frequency bands,
such as, e.g., 1.5 GHz, 1.8 GHz, 5.7 GHz, 6.9 GHz, and/or 7.1 GHz.
Moreover, the antenna assemblies included in the bodypack device
are configured to be completely embedded into the conductive
enclosure of the bodypack device and conform to existing space
within the enclosure, or more specifically, a frame supporting the
enclosure. In addition, the antenna assemblies have a unique
mechanical design that is configured to provide stable antenna
performance and minimum resonance frequency variation during
manufacturing and assembly processes. For example, the assembly
process can include inserting an antenna element subassembly into a
mechanical enclosure (or plastic housing) and connecting an RF
cable of the subassembly to the main circuit board of the bodypack
device.
This disclosure is intended to explain how to fashion and use
various embodiments in accordance with the technology rather than
to limit the true, intended, and fair scope and spirit thereof. The
foregoing description is not intended to be exhaustive or to be
limited to the precise forms disclosed. Modifications or variations
are possible in light of the above teachings. The embodiment(s)
were chosen and described to provide the best illustration of the
principle of the described technology and its practical
application, and to enable one of ordinary skill in the art to
utilize the technology in various embodiments and with various
modifications as are suited to the particular use contemplated. All
such modifications and variations are within the scope of the
embodiments as determined by the appended claims, as may be amended
during the pendency of this application for patent, and all
equivalents thereof, when interpreted in accordance with the
breadth to which they are fairly, legally and equitably
entitled.
* * * * *